Arthroscopic Correction of Pincer-Type FAI in the Presence of Acetabular Retroversion Results in Excellent Patient-Reported Outcomes With Low Risk of Reoperation or Conversion to Arthroplasty at Minimum 5 Years

Background: Acetabular retroversion is a distinct morphologic variation that may result in pincer-type femoroacetabular impingement (FAI). The role of arthroscopic management within this cohort is not fully understood. Purpose: To assess patient-reported outcome measures (PROMs) and survivorship at 5-year follow-up in a series of cases undergoing arthroscopic correction of pincer-type FAI with acetabular retroversion. Study Design: Cohort study; Level of evidence, 3. Methods: A single-center, prospective hip preservation registry was reviewed for all cases undergoing primary hip arthroscopy for symptomatic FAI between January 2014 and July 2020, with documented radiographic assessment of acetabular retroversion (ie, presence or absence of crossover sign, ischial spine sign, and/or posterior wall sign on a standing, standardized anteroposterior radiograph). Exclusion criteria were Tönnis grade >1, concomitant pathologies (protrusio, Perthes disease, avascular necrosis), excessive pelvic rotation or tilt on radiographs, and/or no crossover sign. Cases were assigned to 1 of 2 groups: moderate-global retroversion group (study group: crossover sign plus either or both ischial spine sign and posterior wall sign) or control group (crossover sign only). Case-control (1:1) fuzzy matching was performed based on age (±2 years), sex, and Tönnis grade (exact). Clinical outcome evaluation included assessment of PROMs (modified Harris Hip Score [mHHS], 36-item Short Form [SF36], University of California–Los Angeles Activity Scale [UCLA], Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC]), achievement of Patient Acceptable Symptom State (PASS), satisfaction, rates of revision arthroscopy, and arthroplasty-free survivorship, both preoperatively and 5 years postoperatively. Statistical analysis was performed using SPSS v29. Results: A total of 201 cases (120 global, 81 moderate) in the moderate-global retroversion group were matched with 201 control cases. Mean age was 30.6 ± 10.2 years; the sample was 90% male. The rate of revision arthroscopy was similar: n = 11 (6%) in both groups ( P = .974). No conversion to periacetabular osteotomy (PAO) occurred in either group. Arthroplasty-free survivorship was 98.2% (retroversion group) and 98.8% (control group) (χ 2 = 0.189; df = 1; P = .664). Significant improvements in PROMs from baseline were noted ( P < .001 for all, in both groups). In total, 81% (moderate-global retroversion group) and 73% (control group) were satisfied at 5 years ( P = .103). No significant difference was seen in PASS achievement rates for any of the PROMs between groups: mHHS, 62.1% versus 65.9% ( P = .498); UCLA, 60.0% versus 52.2% ( P = .192); SF36, 59.8% versus 64.7% ( P = .458); WOMAC, 63.5% versus 67.3% ( P = .553), for moderate-global retroversion and control groups, respectively. Conclusion: Hip arthroscopy for moderate and global acetabular retroversion resulted in significant improvement in clinical outcomes, with high satisfaction and arthroplasty-free survivorship at 5 years, consistent with a case-control matched group without acetabular retroversion (focal retroversion, pincer FAI). Arthroscopy alone, without anteverting PAO, was an effective surgical management approach for symptomatic FAI in the presence of acetabular retroversion.